Inside stent placement has been increasingly used for biliary drainage in patients with perihilar biliary strictures 1-3. In cases with separated intrahepatic bile ducts, placement of multiple stents is often required; however, this can be technically challenging. During sequential deployment of multiple stents, insertion of the second stent may lead to unintended dislocation or deep migration of the first stent 4, 5. Recently, a 6Fr inside stent, which is thinner than the conventional 7Fr stent, has become available. A major advantage of the 6Fr system is that two-stent delivery systems can be inserted simultaneously through a therapeutic duodenoscope with a 4.2-mm working channel, enabling a novel deployment strategy. In Video 1, we compare two ERCP cases with perihilar biliary strictures requiring bilateral inside stenting. In the first case, two 7Fr inside stents (Through Gadelius Medical K.K., Tokyo, Japan) were placed sequentially into the anterior and posterior sectoral ducts. During insertion of the second stent, the first stent was displaced distally (Figure 1). In contrast, the second case demonstrates simultaneous placement of two 6Fr inside stents (X-Flex; Olympus Co., Tokyo, Japan). Both stents were deployed after confirming optimal positioning (Figure 2), resulting in smooth placement without stent dislocation. The stents have remained patent without recurrent biliary obstruction at 4 months of follow-up. However, the smaller diameter of the stent may lead to insufficient biliary drainage and shorter stent patency. The thinner structure may also lead to bending of the stent tip in highly angulated ducts, such as the posterior sectoral duct. If plastic stents of 7Fr or larger were available for this technique, they might be preferable. Nevertheless, simultaneous deployment of dual 6Fr inside stents may represent a feasible technical option for multiple stenting in perihilar biliary strictures, potentially reducing technical difficulty and procedure time. A.K. and T.I.: conception. T.I.: acquisition. AK.: drafting the work. T.I. and H.K.: revising. H.K.: final approval. All authors have read and agreed to publish this version of the manuscript. The authors have nothing to report. The authors have nothing to report. The authors have nothing to report. The authors have nothing to report. T.I. is an Associate Editor of Digestive Endoscopy. Other authors declare no conflicts of interest for this article. The data that support the findings of this study are available from the corresponding author upon reasonable request.
越山彩香 et al. (Wed,) studied this question.